Aged 18 going on 19, I already had politics in my blood after a childhood in South Africa, where my parents had been jailed and banned from political activity. Finally we were forced into exile in Britain in 1966, when I was 16. But my belief in socialism really crystallised several years later - around 1968-69 - the years of the Paris uprising, of student agitation throughout Europe and the US, of the Soviet invasion of Czechoslovakia, and of anti-Vietnam War protests. A "new left" had emerged, iconoclastic and just as opposed to capitalism as to Stalinism: "Neither Washington nor Moscow", as the slogan went. A "bottom-up" socialism rather than a "top-down" one, popular participation not state bureaucracy, workers' control not nationalisation - these were the watchwords.
Activists like me in their late teens could immerse themselves in an exciting ferment of new and radical ideas shaped by the passionate debate in teach-ins, conferences, demonstrations and sit-ins. I was soon to adapt non-violent direct action - from student sit-ins at Hornsey College of Art, worker occupations and squats in empty houses - to the anti-apartheid struggle, leading the Stop the Tour protests of 1969-70, which disrupted all-white sports tours by teams from South Africa and isolated the country from international sport.
I also listened to arguments between Marxists and anarchists, socialists and liberals, and I read the burgeoning literature of the contemporary new left voraciously: Noam Chomsky, E P Thompson, Raymond Williams, Ralph Miliband, and many more writers and pamphleteers. But it was George Orwell, a writer of the left from a different era, who seemed to set all this in a more grounded, more mature, and historic perspective in Homage to Catalonia.
I recall it less as the classic it was on the Spanish Civil War, and more as a personal discovery by Orwell of how his democratic socialist instincts had been sharpened and shaped by the buffeting and swirl of the ideological clashes and bitter struggles within the inspirational resistance to Francisco Franco's fascism.
Orwell describes how the left that led this resistance was typically divided between anarchists, syndicalists, communists, Trotskyists and socialists. As he picked his way through the heroism and the horror, the passion and the ulterior purposes of these competing groups, he both experienced all that is best, and worst, about the left.
The best was the extraordinary commitment and dedication to beat Franco. The volunteers who joined the International Brigades made sacrifices for the cause, poorly trained, yet fighting and often dying in a foreign land for their anti-fascist beliefs. The Spanish left lit a fervent flame for community socialism with their agricultural co-operatives and worker collectives, while showing incredible bravery in battle.
The worst was the bitter sectarianism between communists, Trotskyists and anarchists, and the way this crippled the overall resistance, their own ideological objectives and party interests, and thwarted the unity desperately necessary to defeat the enemy. In the case of the communists, their continuing allegiance to Moscow, as Stalin and Hitler were manoeuvring towards a pact, led to betrayals of fellow members of the Resistance.
The Trotskyists in some ways came out better in Orwell's eyes, though they, too, were on the receiving end of his penetrating criticism, which relied not so much on invective as a bluntness of style that I found refreshing. Orwell was never one for flannel - and the left would be a lot healthier even today if his writ ran right across its politics. He was contemptuous of posturing, of striking up positions so as to be seen to follow whatever was deemed the acceptable "line". Equally, he had no time for adventurism or the tendency of Trots, both at the time and later, to pose "transitional demands" that could not be satisfied, but which, from their point of view, would "expose" left-wing opponents as betraying the faith.
I remember Homage to Catalonia, however, not as some dry textbook, but as a gripping narrative, climaxing in the internecine firefight in Barcelona where the left helped defeat itself, and thereby opened the door to Franco's murderous victory and equally murderous rule. Like Orwell's, my socialism was, and remains, "libertarian" rather than "statist". I continue to believe that extra-parliamentary action is a vital force for change, which can prod and thereby complement progressive government. So, Orwell's book not so much changed my life as helped define a set of beliefs that has guided my political life over more than 40 years, both outside and inside government.
Peter Hain is a former Labour cabinet minister and is MP for Neath. His biography of Nelson Mandela will be published this year by Octopus